Isooctane, or 2,2,4-trimethylpentane, is a toxic, flammable, volatile, organic alkane, and an isomer of octane. Available in various quantities and reagent grades, it is an anti-knocking agent in gasoline. Other applications include use as a non-polar solvent.

Isooctane (or iso-octane), also widely known by its IUPAC name 2,2,4-trimethylpentane, C8H18, or CAS 540-84-1, is an organic hydrocarbon alkane and an isomeric form of octane. Structurally, it consists of pentane with two methyl groups at position 2, and a single methyl group at position 4. It is a clear, colorless, volatile liquid, immiscible with water, with a petrol-like odor. Physical data: boiling point 99.3°C; density 0.69g/cm³; melting point −107.3°C.

Uses of Isooctane
• As a general-purpose solvent, thinner, cleaner, and degreaser
• As a component in organic synthesis in the chemistry laboratory
• As a solvent in spectrophotometric analysis
• As a solvent in trace pesticide and herbicide residue analysis
• As a solvent in HPLC

Novel applications include use as an embedding fluid in tissue fixation and histology, while wider industrial applications include use in the manufacture of anti-freezes, coatings, fillers, plasters, clays, paints, lubricants, and biocides.

This product is available in a wide range of grades for specific applications, for example, extra pure/extra-dry for analysis, LC/MS, and HPLC.

Isooctane is a highly flammable liquid, harmful if inhaled, and toxic if released into the environment. Storage in a cool, secure location is therefore recommended. When using this product, the information and advice given in the Safety Data Sheet should be observed. Due attention should also be given to the appropriate precautions necessary for handling chemicals.